@article{MM3_2006_10_1_a13,
     author = {Janez U\v{s}an},
     title = {A {Survey} of {NP\ensuremath{-}Polyagroups}},
     journal = {Mathematica Moravica},
     pages = {149 - 172},
     publisher = {mathdoc},
     volume = {10},
     number = {1},
     year = {2006},
     url = {https://geodesic-test.mathdoc.fr/item/MM3_2006_10_1_a13/}
}